Percentage
Calculator
Three percent tools in one.
Open the percentage calculator →
Percentages
Percentage Decrease Calculator
Decrease a value by a percentage to get the new value and the amount removed.
New value
—
After the decrease.
| Amount removed | — |
|---|---|
| Starting value | — |
| Percent used | — |
Show our math
Enter your figures above to see the step-by-step working.
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How the Percentage Decrease Calculator Works
To decrease a number by a percentage, find that percentage of the starting value and subtract it. This calculator multiplies the starting value by the percentage to get the amount removed, then subtracts it — exactly what you need for discounts, sale prices, depreciation and pay cuts.
The one-step shortcut is to multiply by (1 − percent ÷ 100). Taking 15% off 80 is 80 × 0.85 = 68.
new = start × (1 − percent ÷ 100)
Frequently Asked Questions
How do I decrease a number by a percentage?
Multiply the number by the percentage to get the amount to remove, then subtract it. For example, 80 decreased by 15% is 80 − (80 × 0.15) = 68. Or multiply directly by 0.85.
How do I take a percentage off a price?
Subtract the discount percentage from 100%, turn it into a decimal, and multiply. 20% off means × 0.80. This is the same math a discount calculator uses.
What is the shortcut for a percentage decrease?
Multiply by 1 minus the percentage as a decimal. A 15% decrease is × 0.85; a 30% decrease is × 0.70.
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Open the percent error calculator →